ERROR: there is no unique constraint matching given keys for referenced table "auctions"

Question:

As you might see, i want "auction_values" to be be "reused" by different auctions without duplicating them for every auction... So i don't want a key relation on the "id" field in the auctions table...

In the context of relational
databases, a foreign key is a
referential constraint between two
tables.1 The foreign key identifies
a column or a set of columns in one
(referencing) table that refers to set
of columns in another (referenced)
table. The columns in the referencing
table must be the primary key or other
candidate key in the referenced table.
The values in one row of the
referencing columns must occur in a
single row in the referenced table.
Thus, a row in the referencing table
cannot contain values that don't exist
in the referenced table (except
potentially NULL). This way references
can be made to link information
together and it is an essential part
of database normalization. Multiple
rows in the referencing table may
refer to the same row in the
referenced table. Most of the time, it
reflects the one (master table, or
referenced table) to many (child
table, or referencing table)
relationship.

As Quassnoi points out, it sounds as if you want to have multiple rows in auctions reference single rows in auction_values.

For that the master or referenced table is auction_values and child or referencing table is auction_values.

If on the other hand Alex is right and you want to reference multiple rows in the auction_values you will need another table.

This table will help you convert the many-to-many relationship (which can not be directly realized on the physical database level) to two one-to-many relationships.

Generally you could have this table store ids from the two starting tables and in this way you can associate any combination of the records from auction_values and auctions.

However, this might be too general and you might actually be after a table auction_value_keys (auction_value_key)